1. Field of the Invention
The present invention relates to an image forming device, and in particular, to an image forming device which carries out heat-developing processing by conveying a photosensitive material to a heating section.
2. Description of the Related Art
Japanese Patent Application Laid-Open (JP-A) Nos. 2000-171914 and 2001-356463 and the like have proposed image forming devices which subject an exposed photosensitive material to heat-developing processing so as to form an image on the photosensitive material, and which read, by a scanner, the image formed on the photosensitive material.
In the heat-developing processing section of the above-described image forming device, the heating section is formed by a heat developing drum, a heating plate, or the like. A heater is housed in the heat developing drum or the heating plate, and the interior of the heating section is heated by the heater.
In accordance with such a structure, due to the photosensitive material, which is being conveyed within the heating section, being heated for a predetermined period of time (the time over which the photosensitive material passes through the heating section), i.e., due to the photosensitive material being subjected to heat-developing processing, the exposed image is formed on the photosensitive material
Reproducibility of density and stability, i.e., the ability for the same image to always be formed at the same density on a photosensitive material, is required of the image forming device. The density of the image formed on the photosensitive material depends on the amount of heat in the heat-developing processing (i.e., the heating temperature and the heating time within the heating section). Accordingly, control of the heating temperature within the heating section is carried out at the image forming device.
Further, from the standpoint of the properties of the photosensitive material, the density of the image formed on the photosensitive material also depends on the environment (the temperature and humidity) in which the image forming device is placed. Namely, if the temperature or the humidity varies, even if the amount of heat in the heat-developing processing is kept at a predetermined temperature by the above-described control, fogging and changes in gradation will arise in the image formed on the photosensitive material.
Conventionally, in order to prevent fogging and changes in gradation caused by changes in temperature and humidity, heat-developing processing is carried out on a test photosensitive material at the time when the image forming device is started up. The results are photometrically measured, and after it is confirmed that there are no abnormalities in the temperature and humidity, heat-developing processing is carried out. This processing is called reference strip processing.
Specifically, in a state in which control of the temperature of the interior of the heating section is carried out, a test color photosensitive material, on which a reference pattern has been exposed in advance, is subjected to heat-developing processing and an image is formed. The test image formed on the test photosensitive material is photometrically measured by a calorimeter. The results of photometric measurement and the original test image are compared, and it is confirmed that no deviation in density has arisen.
Here, in cases in which the fogging and changes in gradation are greater than or equal to given values and are problematic, the environment in which the image forming device is disposed is adjusted, i.e., the air conditioning of the room in which the image forming device is placed is adjusted manually. Then, heat-developing processing of a test photosensitive material is carried out again, and after the fogging and changes in gradation are confirmed, heat-developing processing of an actual photosensitive material is carried out.
However, if the environment (the temperature and/or the humidity) of the image forming device changes after heat-developing processing of an actual photosensitive material has begun, the density of the formed image will deviate. Thus, large-scale air-conditioning equipment is needed in order to ensure that the environment does not change.
Further, depending on the history of the photosensitive material which is being processed, there are cases in which the moisture content of the photosensitive material varies. Because, in a short period of time, the moisture content of the photosensitive material does not coincide with the equilibrium moisture content of the environment in which processing is being carried out, there are cases in which the gradation and the fogging of the image greatly vary, which causes trouble in processing.
In view of the aforementioned, an object of the present invention is to provide an image forming device in which there is little fogging, excellent gradation reproducibility and excellent stability, by automatically correcting processing conditions in accordance with the environment in which the image forming device is placed, or in accordance with the history and the state of a photosensitive material.
A first aspect of the present invention is an image forming device subjecting a photographed photosensitive material, in which at least silver halide grains and a developing agent or a precursor of a developing agent are incorporated on a support, to heat-developing processing by conveying the photosensitive material through a heating section, so as to form an image on the photosensitive material, the image forming device comprising a temperature-sensing device, a device humidity-sensing device, a heating device, a first computing device, and a first controlling device. The device temperature is for sensing device sensing a temperature within the image forming device. The device humidity-sensing device is for sensing a humidity within the image forming device. The heating device is for heating an interior of the heating section. The conveying device is for conveying the photosensitive material within the heating section. The first computing device is for computing an optimal value of a heating temperature within the heating section and an optimal value of a heating time, on the basis of the temperature and the humidity sensed by the temperature-sensing device and the humidity-sensing device. The first control device is for controlling a heating temperature by the heating device and/or a photosensitive material conveying-speed by the conveying device, such that at least one of the optimal values is attained.
In accordance with the first aspect, the device temperature-sensing device senses the temperature within the device, and the device humidity-sensing device senses the humidity within the device. The temperature and humidity within the device affect the fogging and the gradation of the image formed on the photosensitive material.
Further, the fogging and the gradation of the image formed on the photosensitive material also depend on the heating temperature within the heating section and the heating time. Namely, the heating temperature within the heating section and the heating time are parameters of the fogging and the gradation of the image formed on the photosensitive material.
Here, the first computing device computes an optimal value of the heating temperature within the heating section and an optimal value of the heating time, on the basis of the sensed temperature and humidity. Then, the first control device controls the heating temperature by the heating device or the photosensitive material conveying-speed by the conveying device such that at least one of the optimal values is attained.
In this way, the optimal value of at least one of the heating temperature within the heating section and the heating time, which affect the fogging and the gradation of the image, offsets the xe2x80x9cdeviationxe2x80x9d of the fogging and of the gradation which arise in the image formed on the photosensitive material in accordance with the change in the temperature and the humidity within the image forming device.
Accordingly, in accordance with the change in the temperature and the humidity within the image forming device, at least one of the heating temperature within the heating section and the heating time is adjusted. Therefore, the xe2x80x9cdeviationxe2x80x9d of the fogging and of the gradation, which arise due to changes in the temperature and the humidity, can be corrected.
A second aspect of the present invention is an image forming device subjecting a photographed photosensitive material, in which at least silver halide grains and a developing agent or a precursor of a developing agent are incorporated on a support, to heat-developing processing by conveying the photosensitive material through a heating section, so as to form an image on the photosensitive material. The image forming device comprises a loading section, a temperature-sensing device, a moisture content sensing device, a heating device, a conveying device, a second computing device, and a second controlling device. The loading section is the section where the photosensitive material is loaded. The temperature-sensing device is for sensing a temperature of the photosensitive material loaded in the photosensitive material loading section. The moisture content sensing device is for sensing a moisture content of the photosensitive material loaded in the photosensitive material loading section. The heating device is for heating an interior of the heating section. The conveying device is for conveying the photosensitive material within the heating section. The second computing device is for computing an optimal value of a heating temperature within the heating section and an optimal value of a heating time, on the basis of the temperature and the moisture content sensed by the photosensitive material temperature-sensing device and the moisture content sensing device. The second control device is for controlling a heating temperature by the heating device and/or a photosensitive material conveying-speed by the conveying device, such that at least one of the optimal values is attained.
In accordance with the second aspect of the present invention, the photosensitive material temperature-sensing device senses the temperature of the photosensitive material loaded in the photosensitive material loading section, and the moisture content sensing device senses the moisture content of the photosensitive material loaded in the photosensitive material loading section. The temperature and the moisture content of the photosensitive material affect the fogging and the gradation of the image formed on the photosensitive material.
Further, the fogging and the gradation of the image formed on the photosensitive material also depend on the heating temperature within the heating section and the heating time. Namely, the heating temperature within the heating section and the heating time are parameters of the fogging and the gradation of the image formed on the photosensitive material.
Here, the second computing device computes an optimal value of the heating temperature within the heating section and an optimal value of the heating time, on the basis of the sensed temperature and moisture content of the photosensitive material. Then, the second control device controls the heating temperature by the heating device or the photosensitive material conveying-speed by the conveying device such that at least one of the optimal values is attained.
In this way, the optimal value of at least one of the heating temperature within the heating section and the heating time, which affect the fogging and the gradation of the image, offsets the xe2x80x9cdeviationxe2x80x9d of the fogging and of the gradation which arise in the image formed on the photosensitive material in accordance with the change in the temperature and the moisture content of the photosensitive material.
Accordingly, in accordance with the change in the temperature and the moisture content of the photosensitive material, at least one of the heating temperature within the heating section and the heating time is adjusted. Therefore, the xe2x80x9cdeviationxe2x80x9d of the fogging and of the gradation, which arise due to changes in the temperature and the moisture content of the photosensitive material, can be corrected.
More concretely, in the first aspect of the present invention, the optimal value of the heating temperature and the optimal value of the heating time are computed by the first computing device so as to offset the change in the density of the image formed on the photosensitive material due to the temperature or the humidity within the device.
Namely, the correlation between, on the one hand, the fogging and the change in gradation of the image formed on the photosensitive material, and, on the other hand, the temperature or the humidity within the device, can be measured and determined in advance. Therefore, the optimal value of the heating temperature and the optimal value of the heating time can be computed from this correlation.
Further, in the second aspect of the present invention, the optimal value of the heating temperature and the optimal value of the heating time are computed by the second computing device so as to offset the change in the density of the image formed on the photosensitive material due to the temperature or the moisture content of the photosensitive material.
Namely, the correlation between, on the one hand, the fogging and the change in gradation of the image formed on the photosensitive material, and, on the other hand, the temperature or the moisture content of the photosensitive material, can be measured and determined in advance. Therefore, the optimal value of the heating temperature and the optimal value of the heating time can be computed from this correlation.
The following are modes for implementing the present invention, but the present invention is not limited to these modes:
(1) A coupler, which reacts with an oxidant of a developing agent and forms a dye, may be incorporated on a support in the photosensitive material.
(2) The present invention may include a heating section temperature-sensing device which senses the temperature of the interior of the heating section, and on the basis of the temperature sensed by the heating section temperature-sensing device, the first control device and the second control device may control output of the heating device such that the heating temperature becomes an optimal value.
(3) Concurrently with above (2), a coupler, which reacts with an oxidant of a developing agent and forms a dye, may be incorporated on a support in the photosensitive material.
Further, in accordance with the second aspect of the present invention, the interior of the heating section is heated by the heating device, and the temperature is sensed by the heating section temperature-sensing device. On the basis of the temperature sensed by the heating section temperature-sensing device, the first control device and the second control device control the output of the heating device, and control the temperature such that the interior of the heating section becomes the optimal temperature.
Namely, the heating section temperature-sensing device is provided separately from the device temperature-sensing device and the photosensitive material temperature-sensing device. For example, when the temperature of the heating section decreases due to heat moving to the photosensitive material while the photosensitive material is undergoing heating processing, this decrease in temperature is sensed by the heating section temperature-sensing section. The first control device and the second control device receive this information, and effect control so as to increase the output in order to return the heating section to its original, optimal temperature.